Category Archives: Environmental


Scientists hope to develop ballast water treatment

Ballast water is great for stabilizing a ship in rough waters. Unfortunately, it is equally great at carrying all sorts of aquatic organisms across the world before releasing them into new ecosystems where many of them become problematic invasive species.

The cost of invasive species in the Great Lakes of North America have now reached $200 million a year and scientists predict that this number will increase sharply if the dreaded fish virus known as VHS manage to hitchhike its way into Lake Superior. Considering the number of international shipping vessels that arrive to this river system each week, it is probably just a matter of time unless drastic measures are put in place to stop the costly carrying of disruptive stowaways.

Ballast

Is ballast treatment the solution?
On-board ballast treatment systems have been proposed by parts of the shipping industry as well as by many scientists, but so far, no one has been able come up with an efficient, cost-effective and safe solution that will work in both freshwater and saltwater. Researchers from the Lake Superior Research Institute* in Superior are now trying to change this.

“The question is how clean is clean? Zero would be great, but is it achievable?” asks Mary Balcer, director of the Lake Superior Research Institute.

Balcer, her research team and students at the University of Wisconsin-Superior are currently analyzing a long row of different solutions developed by private companies to see if any of them could help protect environments such as the Great Lakes from the threat of marauding newcomers.

The goal is to find a solution that will eliminate as many living organisms as possible before the ballast water is released. The treatment must also be safe for the ecosystem into which the water will be released.

Freshwater more demanding
Last month, researcher Tom Markee and several students tested using chlorine to eliminate organisms such as tiny worms, midges and water fleas growing in fish tanks in the university lab. Carrying large containers of chlorine on a ship is naturally dangerous, so Markee and his team instead opted for a solution where the treatment system produces its own chlorine by exposing saltwater to an electric current. The goal for Markee et al is now to find the ideal dose of chlorine as well as make sure that the system works in different types of water.

They’ve tested it in saltwater and it works fine, but when you get to harbors or a river system, that’s when it becomes less effective,” Markee explains.

Other examples of techniques that are being explored by the research institute are the use of ultraviolet light, ozone and even lethal inaudible sound.

Balcer says her research team hasn’t yet found any viable treatment system that would kill all the living organisms in a ballast tank, but she’s happy with the progress that’s been made.

“Everyone’s behind getting the problem solved,” she says. Eventually we’ll be able to find something that really works.”

* Lake Superior Research Institute, http://www.uwsuper.edu/wb/catalog/general/2006-08/programs/LSRI.htm

Fishermen hired to clean up their pots

crab fishingTens of thousands of crab pots litter the ocean floor, forming lethal obstacle courses of plastic lines and weighed-down metal cylinders. Lost crab pots are responsible for killing a long row of air breathing ocean dwellers, such as whales, sea lions and turtles. In addition to their effect on marine wildlife, stray crab pots also inflict costly and potentially dangerous damage to passing vessels.

The basic type of crab pot is a squat cylinder consisting of steel mesh and rubber, and with heavy iron that helps it sink to the bottom. Fishermen lose track of their crab pots due to various reasons, including storms, tousling kelp banks, and passing motor vessels that snaps of the line between the pot and the buoy.

In the past five years, two dead whales have washed up on the Oregon Coast entangled in the fatal combination of metallic pots and durable synthetic lines, but a federal stimulus grant of $700,000 from the National Oceanic and Atmospheric Administration has now been assigned to pay Oregon fishermen for cleaning up their crab pots – or at least a fraction of them.

As the crab season ends in August, the federal money will be used to charter 10 boats and hire 48 people — including the 31 fishermen who make winning bids. The aim is to recover 4,000 pots over two seasons.

Each year, Oregon fishermen lose 10 percent of the 150,000 pots they put out, according to a statement from Cyreis Schmitt, marine policy project leader at the Oregon Department of Fish and Wildlife.

Mouse-deer swims underwater to escape predators

mouse deerTwo species of Asian mouse-deer have been observed utilizing a very interesting technique to get away from predators; they jump into the water and stay there until its safe to come up. By carefully swimming up to the surface to breathe now and then they can stay submerged for long periods of time.

People living in the Indonesian country side have always claimed that deer hide in the water when chased by their dogs, but it wasn’t until the behaviour was observed by a team of scientists doing a biodiversity survey that it caught the attention of the larger scientific community.

In June 2008, the team visited the northern Central Kalimantan Province in Borneo, Indonesia where they suddenly spotted a mouse-deer swimming in a forest stream. When the deer understood that it was being watched by humans, it went below the surface and remained hidden. Over the next hour, team members could see it come to the surface four or five times. Although it probably went up for air a few more times without being noticed, it could clearly remain submerged for more than five minutes at a time.

Eventually, the researchers caught the animal and photographed it before releasing it back into the wild unharmed. It was a pregnant female deer.

One of the members of the team is the wife of Erik Meijaard, a senior ecologist working with the Nature Conservancy in Balikpapan, Indonesia. When she showed her husband the photograph, he identified it as a Greater mouse-deer (Tragulus napu).

That same years, another group of observers witnessed a Mountain mouse-deer (Moschiola spp) throwing itself into pond and swimming under water to get a way from a hungry mongoose in Sri Lanka. The mongoose followed it into the pond, but eventually retreated as the deer continued to stay submerged.

“It came running again and dived into the water and swam underwater. I photographed this clearly and it became clear to me at this stage that swimming was an established part of its escape repertoire,” says Gehan de Silva Wijeyeratne, who saw the incident.

“Seeing it swim underwater was a shock”, he says. “Many mammals can swim in water. But other than those which are adapted for an aquatic existence, swimming is clumsy. The mouse-deer seemed comfortable, it seemed adapted.”

Both incidents have now been described in the journal “Mammalian Biology”.

“This is the first time that this behaviour has been described for Asian mouse-deer species,” says Meijaard. “I was very excited when I heard the mouse-deer stories because it resolved one of those mysteries that local people had told me about but that had remained hidden to science.”

What is a mouse deer?

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Tragulidae

Mouse deer are small deer-like animals with large upper canine teeth. In male specimens you can even see the teeth project down either side of the lower jaw. Ten different species of mouse-deer have been described by science and all except one live in South-East Asia. The Water Chevrotain (Hyemoschus aquaticus) is the only mouse deer native to the African continent and it is also the largest member of the family.

The Water Chevrotain (Hyemoschus aquaticus) lives in swampy habitats and is known to dash into the nearest river as soon as it is spooked by something. Until recently, this was the only mouse deer in which the habit of swimming under water and staying submerged for long periods of time had been described and all the Asian members of the family Tragulidae were thought to be strictly dry-land animals.

Virginia catfish boom

Specimens of the invasive Blue catfish (Ictalurus furcatus) have now grown large enough to reach the top of the food chain in James River, Virginia. A catfish weighing 102 lbs (46 kg) was caught from the river not long ago; the largest caught freshwater fish ever to be reported from Virginian waters.

30 years ago, Blue catfish was deliberately introduced to this U.S. river as a game fish. During recent years, the catfish population has grown explosively while many other fish species have decreased. An eight year old Blue catfish normally weigh a mere 4 lbs (1.8 kg), but as soon as it gets large enough to start catching other fish and devouring fully grown crabs, it begins putting on weight at a rapid pace and can gain as much as 10 lbs (4.5 kg) a year.

Picture of blue catfish - Ictalurus furcatus
Blue Catfish – Ictalurus furcatus. Copyright www.jjphoto.dk

According to Bob Greenlee, a biologist with the state Department of Game and Inland Fisheries, scientists doing sampling used to get around 1,500 catfish in an hour in this river in the 1990s. Today, this number has increased to 6,000. “We have an invasive species that is taking over the ecosystem,” says Rob Latour, a marine biologist with the Virginia Institute of Marine Science at the College of William and Mary.

Florida Keys’ reefs have diminished by 50 to 80 percent in the past 10 years, researcher says

reef“For the Florida Keys’ reefs, overall, the live coral cover has diminished by 50 to 80 percent in the past 10 years,” says Margaret Miller, a coral reef researcher at the National marine Fisheries Service. According to Miller, the destruction is the result of several contributing factors, such as pollution, climate change, over-fishing, and coastal developments.

“Corals are very susceptible to warming temperatures, because their lethal temperature [temperature at which they die] and their happy, normal temperature are very close, only separated by a couple of degrees,” Miller explains.

The reef building corals are not the only creatures in trouble in Florida; the situation looks dire for many reef associated species as well.

University of Miami marine professor Jerry Ault has studied marine life in the region for more than a decade.
“The research has discovered that about 70 percent of all the snapper and grouper in the Florida keys reef system are at population levels below those considered to be sustainable,” he said. “Everybody loves Florida because of the marine environment. Folks come here to fish and to dive and to take advantage of it, but we are loving it to death.”

Giant underwater blood suckers making a comeback

Sea Lamprey spawning sites have been discovered in the River Wear at Chester-le-Street, County Durham, by local anglers. After being alerted by the fishermen, the Environment Agency found no less than 12 spawning sites, known as redds, measuring up to a metre across.

We were thrilled to discover lampreys back in the River Wear as these rare blood-suckers show us that the water quality in the river is very high“, says Environment Agency fisheries officer Paul Frear. “Lampreys are extremely selective with their spawning sites and will only nest where the water quality is optimal. Today, only three species of this blood-sucking creature remain in Britain and their habitats are protected by an EC directive.”

The lamprey feeds by attaching itself to another animal with its suction-cup like mouth and, once in place, gradually rasps away tissue from its host. The largest specimens are roughly 100 cm long, but most lampreys are smaller than this.

If you see a lamprey or a lamprey redd (nest) in the UK, please report the sighting directly to Paul Frear by e-mailing him at paul.frear@environment-agency.gov.uk.

As reported earlier, invasive sea lampreys have caused serious problems in North America where they lack natural enemies.

lamprey
Picture is from North America where the lamprey have caused serious problems.

Lungfish died caught in trees

Up to 50 lungfish, some of them up to on metre long, was killed when tonnes of water was released from an Australian dam this week.

The water was released from the North Pine Dam in southeast Queensland between Monday morning and Tuesday night as heavy rains were threatening to overfill the dam.

According to SEQWater, who manages the North Pine Dam, up to 100 native fish went with the release, including roughly a dozen lungfish. SEQWater spokesman Mike Foster said staff were on the scene at every dam release to check for “fish kills” and that they had rescued a handful of lungfish from pools. He also stated that staff would return on Thursday [today] to see if more could be done.

In May, when the North Pine Dam opened its gates for the first time in many years, up to 150 lungfish were rescued.

Roger Currie, spokesman for the Wide Bay Burnett Conservation Council, said conservationists on the scene during the most recent water release had found up to 50 lungfish that had been killed or mutilated as a result of the release.

“Some were found caught in trees yesterday and last night,” Currie said. “They’ve just been pummelled by the sheer force of it.”

The Wide Bay Burnett Conservation Council is pushing for a study to find out how large the North Pine Dam lungfish population is, and the council is also calling for measures to protect fish during water releases.

neoceratodus forsteri  picture
Lungfish of the species Neoceratodus forsteri.
Copyright www.jjphoto.dk

What’s so special about the Australian lungfish?
The Queensland lungfish, Neoceratodus forsteri, is the only now living member of the family Ceratodontidae and order Ceratodontiformes. Also known as Australian lungfish or Barramunda, Neoceratodus forsteri is native only to the Mary and Burnett river systems in south-eastern Queensland. It has however been introduced to several other Australian rivers south of this area during the past century.

Fossil records of the lungfish group date back 380 million years to a period when the higher vertebrate classes were at the starting point of their development. Prehistoric fossils unearthed in New South Wales are almost identical to the now living Qeensland lungfish, indicating that this species hardly has evolved at all during the last 100 million years. Lungfishes flourished during the Devonian period (c. 413-365 million years ago) but only six species of freshwater lungfish remain today; one in Australia, one in South America, and four in Africa.

The Queensland lungfish can survive for several days out of water, but only if kept moist. It can breathe oxygen directly from the air using its lung-like swim bladder. This species is remarkably long-lived compared to most other fish species and will usually attain an age of at least 20-25 years if it manages to survive into adulthood. Granddad, a Queensland lungfish living at the Shedd Aquarium in Chicago, is at least 80 years old. He has been housed at the aquarium since 1933 and seen many generations of zoo keepers come and go. The largest

Plastic rubbish a problem says UN study

The United Nations Environment Program has now released the first study of the impact of marine debris throughout the world’s oceans. The report found that plastic, especially bags and polyethylene terephthalate (PET) bottles, makes up more than 80 per cent of all rubbish found in the oceans. The UN report, titled “Marine Litter: a Global Challenge”, also found that plastic bags alone constitute almost 10 percent of the rubbish.

Some of the litter, like thin-film, single-use plastic bags, which choke marine life, should be banned or phased out rapidly everywhere because there is simply zero justification for manufacturing them any more, anywhere,” says UN environment program executive director Achim Steiner.

The United Nations are not the only ones worried about the enormous amounts of plastic entering our marine ecosystems each year. In Australia, plastic bags and other marine debris are a direct threat to 20 marine species according to the Federal Government’s Threatened Species Scientific Committee who has listed plastic bags as a “key threatening process” under the Environment Protection and Biodiversity Conservation Act 1999. Marine animals threatened by our reckless use of plastics include iconic creatures like the Blue whale, Loggerhead turtle, and Tristan albatross.

Record breaking Gulf of Mexico ‘Dead Zone’ this summer

gulf of mexicoAccording to predictions made by a team of NOAA-supported scientists from the Louisiana Universities Marine Consortium, Louisiana State University, and the University of Michigan, the Gulf of Mexico “dead zone” is likely to become record big this summer. If there predictions are true, we will see a dead zone the size of New Jersey (7,450 to 8,456 square miles). Additional flooding of the Mississippi River since May can however increase these numbers even further.

What is the Gulf of Mexico ‘dead zone’?

The dead zone is an area off the coast of Louisiana and Texas in the Gulf of Mexico where the oxygen level seasonally drops so low that most life forms living in and close to the bottom dies.

Dead zones are the result of large amounts of nutrients reaching the water, e.g. through waterways polluted by sewage and agricultural runoff. The excess nutrients stimulate rapid and massive algae growth in the affected area, a so called algae bloom. When the algae die, they sink to the bottom where oxygen dependant bacteria begin to break them down. The decomposition process consumes vast amounts of oxygen and soon the bottom and near-bottom waters become so oxygen depleted that all sorts of oxygen breathing organisms begin to die. This so called hypoxic area (an area where the oxygen levels are low to non-existent) is not just a problem for wildlife; it can also damage the economy of nearby states since it destroys habitat necessary for commercial and recreational Gulf fisheries.

The largest dead zone on record appeared in 2002 and measured 8,484 square miles.

Mississippi and Atchafalaya Rivers too rich in nutrients

During April and May this year, the Mississippi and Atchafalaya Rivers experienced heavy water flows that were 11 percent above average.

The high water volume flows coupled with nearly triple the nitrogen concentrations in these rivers over the past 50 years from human activities has led to a dramatic increase in the size of the dead zone,” said Gene Turner, Ph.D., a lead forecast modeler from Louisiana State University.

As with weather forecasts, this forecast uses multiple models to predict the range of the expected size of the dead zone“, said Robert Magnien, Ph.D., director of NOAA’s Center for Sponsored Coastal Ocean Research. “The strong track record of these models reinforces our confidence in the link between excess nutrients from the Mississippi River and the dead zone.”

Get ready to swim with the jellyfish

During recent years, massive jellyfish congregations have appeared along the Northeast U.S. coast, in the Gulf of Mexico, in the Mediterranean, in the Black and Caspian Seas, and in South-East Asian coastal waters.

Dense jellyfish aggregations can be a natural feature of healthy ocean ecosystems, says Dr Anthony Richardson of the University of Queensland, but a clear picture is now emerging of more severe and frequent jellyfish outbreaks worldwide.”

A new study by Richardson and his colleagues at the University of Miami, Swansea University and the University of the Western Cape, presents convincing evidence that these massive jellyfish populations are supported by the release of excess nutrients from fertilisers and sewage, and that fish populations depleted by over-fishing no longer are capable of keeping them in check.

Fish normally keep jellyfish in check through competition and predation but overfishing can destroy that balance,” Dr Richardson says. “For example, off Namibia intense fishing has decimated sardine stocks and jellyfish have replaced them as the dominant species. Mounting evidence suggests that open-ocean ecosystems can flip from being dominated by fish, to being dominated by jellyfish. This would have lasting ecological, economic and social consequences.”

In addition to this, the distribution of many jellyfish species may extend as a response to global warming and an increased water temperature could also favour certain species by augmenting the availability of flagellates in surface waters.

The study, which was lead by CSIRO Climate Adaptation Flagship, has been published in the journal Trends in Ecology and Evolution.

You can find more information about CSIRO Climate Adaptation Flagship here:

450 pound blobs filling up the Sea of Japan

sea of japanThe changing ecosystems affect a long row of different jellyfish species, but some of the most spectacular jellyfish congregations observed during recent years have involved the Nomura jellyfish (Nemopilema nomurai) living in the Sea of Japan (Also known as the East Sea). This colossal species, which can reach a size of 2 metres* across and weigh up to 220 kg**, is also present in the Yellow Sea as well as in the rest of the East China Sea.

After becoming a major problem in the region, the Nomura jellyfish population is now combated by a special committee formed by the Japanese government. Killing jellyfish or ensnaring them in nets will however only prompt these animals to release billions of sperm or eggs; aggrevating the problem rather than reducing it. Coastal communities in Japan have started to harvest jellyfish and sell them as a dried and salted snack, and students in Obama, Fukui have started making jellyfish cookies and jellyfish-based tofu.

* circa 6 feet 7 inches

** circa 450 pounds